1. Field of the Invention
The present invention relates to an electric vacuum cleaner having a dust suction duct that is connected to a nozzle unit.
2. Description of the Prior Art
A conventional electric vacuum cleaner of a so-called upright type is typically composed of a nozzle unit having a nozzle, a main body supported so as to be bendable back and forth with respect to the nozzle unit and incorporating a dust collection bag, and a handle portion by which a user holds the main body so that he can move the electric vacuum cleaner around. Advantageously, when not in use, such an upright-type electric vacuum cleaner can be stored away with its main body in an upright position.
However, to permit such an electric vacuum cleaner to be stored away in an upright position, its heavy main body needs to be supported on its nozzle unit facing the floor surface so that the electric vacuum cleaner does not turn over. Thus, the nozzle unit needs to be made accordingly large, and consequently requires a considerably large storage space.
In addition, since the main body is directly pivoted on the large nozzle unit, electric vacuum cleaners of this type are unfit for the cleaning of narrow spaces such as gaps between pieces of furniture. Some models come with relatively small nozzle units, but they instead require dedicated stands or the like on which they need to be put when stored away. This seriously limits the choice of where to store away such electric vacuum cleaners.
An object of the present invention is to provide an electric vacuum cleaner that can be stored away with its main body in an upright position, and thus with less space, and that is built in a way advantageous to the downsizing of its nozzle unit.
To achieve the above object, according to the present invention, in an electric vacuum cleaner provided with an electric blower, a nozzle unit having a nozzle, and a dust suction duct fitted between the electric blower and the nozzle unit so as to serve as a passage for a dust suction air flow generated by driving the electric blower, the dust suction duct is bendable at some point along itself and can stand in an upright position by itself. This makes the downsizing of the nozzle unit possible, and in addition permits the electric vacuum cleaner to be stored away almost anywhere and with minimum space when not in use.
The dust suction duct may be composed of a first dust suction duct of which one end is joined to the nozzle unit and a second dust suction duct that is rotatably joined to the other end of the first dust suction duct. This permits the second dust suction duct to be rotated so as to be held in an upright position.
One end of the first dust suction duct may be rotatably joined to the nozzle unit. This makes it possible to rotate the first dust suction duct separately from the rotation of the second dust suction duct.
An electric vacuum cleaner according to the present invention may be further provided with a locking mechanism that, when the first and second dust suction ducts come into a substantially straight state, locks the first and second dust suction ducts to keep them in the substantially straight state. In this arrangement, when the second dust suction duct is rotated so that the first and second dust suction ducts come into a substantially straight state, they are locked in that state. This enhances cleaning efficiency.
The nozzle unit may be removable integrally with the first and second dust suction ducts. This makes it possible to perform cleaning with an auxiliary nozzle, instead of the nozzle unit, fitted to the tip of the dust suction duct.
An electric vacuum cleaner according to the present invention may be further provided with a cyclone-type dust collector portion fitted at some point along the dust suction duct so as to separate the dust sucked in through-the nozzle unit by whirling around the dust suction air flow generated by driving the electric blower.
In this arrangement, the dust suction air flow generated by driving the electric blower turns into a whirling air flow inside the cyclone-type dust collector portion, and the centrifugal force exerted by this whirling air flow separates dust. The dust thus separated is accumulated inside the cyclone-type dust collector portion.
The second dust suction duct may be rotatable up to more than 90 degrees from the position in which the first and second dust suction ducts are in a substantially straight state. In this arrangement, the second dust suction duct, when held in an upright position, inclines toward the nozzle unit and thereby prevents the electric vacuum cleaner from turning over.
An electric vacuum cleaner according to the present invention may be further provided with means for stopping the driving of the electric blower when, at the joint between the first and second dust suction ducts, the second dust suction duct is rotated to a predetermined rotation angle. In this arrangement, when the dust suction duct is obstructed at the joint, even if a power switch for starting the driving of the electric blower is turned on, the electric bower does not start being driven.
A shock absorbing member may be fitted in a portion of the first dust suction duct at which it makes contact with the floor surface. The shock absorbing member absorbs the shock that occurs when the first dust suction duct collides with the floor surface as it is rotated so that the main body is held in an upright position. This prevents the first dust suction duct from being scratched or broken.
A caster may be fitted on the first dust suction duct so as to permit the nozzle unit to be moved around on the floor surface. This permits the nozzle unit to be moved around with the first dust suction duct kept in contact with the floor surface even on a thick-piled carpet, and thus makes cleaning easy.